Hole punching tool

ABSTRACT

A tool for forming pilot holes disposed accurately in a utility passage cover or the like through a layer of flooring. A circle saw uses the pilot holes to cut larger holes through the utility passage cover via an opening formed through a layer of flooring material overlying the utility passage. The tool comprises an elongate staff terminating in a punch portion at one end thereof. An anvil element is carried by the staff at one end and a hammer element is carried by and movable along the staff into and out of engagement with the anvil element for striking blows thereagainst to drive the punch. Guide means carried about the punch portion engage the side walls of the opening to accurately position the punch. The punch element moves freely through the guide during driving of the punch.

ited States atent @arver HOLE PUNCHING TOOL Primary Examiner-Jamcs L.Jones. Jr. Assistant ExaminerJ. C. Peters [76] Inventor gg'gizx f i i ig 52 5; Attorney, Agent, or Firm-Flehr, l-lohbach, Test, Al-

britton & Herbert [22] Filed: Mar. 23, 1972 [21] Appl. No.: 237,451 [57]ABSTRACT A tool for forming pilot holes disposed accurately in a [52]U.S. Cl. 30/367 tflit a a ver the like through a layer of [51 lillll. ClB26 1/24 flooring A circle saw uses the pilot holes to cut larger [58]Field of Search 30/277, 367, 368, 358; holes th h the utility passagecover via an opening 8 /5 173/91 formed through a layer of flooringmaterial overlying the utility passage. The tool comprises an elongateReferences Cited staff terminating in a punch portion at one end UNITEDSTATES PATENTS thereof. An anvil element is carried by the staff at one2,787,179 4/1957 Warner 30/367 x end and a hammer element is carried byand movable 3,039,467 6/1962 Stone 30/367 x along the Staff into and outof engagement with the 722,559 3/1'903 Bond 30/368 X anvil element forstriking blows thereagainst to drive 2,795,052 6/1957 Felenchak....30/368 X the punch. Guide means carried about the punch por- 54,5857/1956 Green 30/277 tion engage the side walls of the opening toaccurately 3,036,482 5/1962 Kenworthy 30/277 X ition the unch The punchelement moves freely through the guide during driving of the punch.

10 Claims, 5 Drawing Figures Patented Feb. 12, 1974.

nous PUNCHING TOOL BACKGROUND OF THE INVENTION This invention pertainsto a hole punching tool for driving or punching holes into the bottom ofa cylindrical or other passageway or opening and is particularly usefulin the punching of pilot holes for circle saws in making access intoutility passages or ducts employed in building construction.

A primary use of the hole punching tool as described herein pertains tothe application wherein a utility passage is located beneath a layer ofconcrete in a building construction.

Generally, in new construction, utility passageways are formed in abuilding and then embedded or submerged beneath a layer of flooringmaterial, such as concrete. Later, when the floor plan is known and thelocation of all of the utility outlets is determined, circular holes arecut by circle saws through the concrete flooring down to the metal coverof the utility passageway. Subsequently, using a circle saw, a circularopening is formed through the cover in a manner whereby the diameter ofthe hole through the metal cover is slightly smaller than the holeformed through the concrete so as to provide a lip which is useful inretaining certain types of utility outlet liners or fixtures which mustbe positioned or driven axially, into the concrete hole to engage thelip surrounding the hole formed through the metal cover.

In the construction of a new building, great numbers of these utilityopenings must be provided even though they are not all immediately usedin order to provide great flexibility in determining a floor plan forthe office or other space to be located in the building.

It is readily evident that, if the circular lip as above described isnot exactly concentric with the cylindrical opening formed through theconcrete, it will not be possible to properly seat certain of the morepopular types of sleeves which fit coaxially within the opening anddepend upon proper inter engagement between the lip and a groove formedin the exterior of and about the lower end of the inserted sleevefixture;

Accordingly, there is a substantial need for quickly forming a pilothole located dead center, or otherwise accurately positioned, of autility outlet opening. In this manner, a circle saw can be employed,guided by the pilot hole, to provide acoaxially aligned hole through thetop of the utility passage.

SUMMARY OF THE INVENTION AND OBJECTS In general, there has been provideda punch, an anvil portion carried by the punch to be struck a sharp blowfor advancing the punch, a guide plate encircling the punch and having alateral expanse corresponding substantially to the lateral expanse ofthe hole formed through flooring, for example, and thereby serving toguide the punch centrally of the hole. Resilient means carried betweenthe upper end of the punch and the guide plateserves to eject the punchaxially along the opening through which it is positioned and after ithas been struck by a hammer.

In general, it is an object of the present invention to provide animproved hole forming tool foraccurately forming pilot holes in autility passage cover or the like via an opening formed through a layerof flooring or other material overlying the utility cover.

It is another object of the present invention to provide a tool of thekind described above incorporating resilient means for ejecting thepunch element from the access hole formed through the flooring materialafter each blow is struck against the punch element and preferably in asubstantially straight line.

The foregoing and other objects of the invention will become morereadily evident from the following detailed description of preferredembodiments when considered in conjunction with the accompanyingdrawmgs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation centerlinesection view showing the invention;

FIG. 2 is a front elevation view according to the invention;

FIG. 3 is an elevation view partly in centerline section according toanother embodiment of the invention;

FIG. 4 is an elevation view of the embodiment shown in FIG. 3;

FIG. 5 is an elevation view of another embodiment of the invention;

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS A hole forming tool 10which is generally operated in an upright manner to drive or punch holesinto metal utility or cable passages 1 1 located beneath the flooring 12of new construction includes an elongate steel staff 13 formed at itslower end with a re-entrant opening 14 for receiving the threaded upperend of an elongated punch element 16 terminating at its other end in asharp point.

The exterior of the lower end of staff 13 is threaded and carriesthereon a steel or other rigid, metal impact collar 17 in the form of athreaded nut or other element made fast to the lower end of staff 13 bymeans of welds 18 or other suitable means.

As thus arranged, a hammer element 19 in the form of an elongate sleeveis slidably mounted upon staff 13 for movement between advanced andretracted positions as indicated by arrow 21 whereby the lower end ofhammer element 19 may move into and out of engagement with the uppersurface of collar 17.

Accordingly, the lower end of hammer element 19 is provided withsuitable means such as a nut 22 threaded onto the exterior threads ofhammer element 19 and made fast thereto, again simply by means of thewelds 23 or other suitable means.

Means have been provided for guiding punch element l6 accurately withina circular opening 24 cut downwardly through the flooring material 12such as concrete as now to be described.

A circular guide plate 26 having a radial expanse correspondingsubstantially to the radial expanse of the circular opening 24 includesa center opening 27 through which punch element 16 may advance andretract. Plate 26 is yieldingly supported to float about punch element16 by means of the three guide rods 28 encircled respectively byhelicalsprings 29 captured between plate 26 and a transversely extendingsupport plate 31 carried at the end of staff 13 and formed with openings32 aligned with similar openings 33 in plate 26. The outer ends of guiderods 28 carry nuts or are formed with a stud head so as to define andadjust the spacing between plates 26 and 31 in a manner whereby plate 26will not become dislodged from the end of tool 10.

Plate 31 is tightly held by means of a lock nut 34 to the lower end oftool by tightening lock nut 34 sufficiently to capture plate 31 betweenlock nut 34 and the bottom of impact collar 17.

In operation, according to the above described embodiment, a suitablepunch element 16 is threadedly engaged in readily releasable coupledrelationship to the lower end of staff 13 simply by screwing the headthereof into opening 14. When it is desired to punch a starter hole fora circle saw centrally of one of the openings 24, guide plate 26 isfirst inserted so as to register substantially with the side walls ofopening 24 and thereby align the center of opening 24 with punch 16.

Hammer element 19 can then be raised until arrested as, for example, bythe nut 35 threaded onto the upper end of staff 13 and then droppedsharply downwardly until the lower end of hammer element 19 strikesimpact collar 17. This action serves to transmit a sharp blow to impactcollar 17 and, accordingly, to punch 16. This action should besufficient to drive a starting hole centrally into the opening 24 in theusual circumstance. However, in the event that additional blows arerequired, it is readily evident that additional blows can be appliedwithout losing registration of the punch with the pilot opening 37 beingformed into the top of utility passage 11.

Immediately following impact, springs 19 compress, plate 31 movesdownwardly against spring pressure guided by rods 28, and thereaftersprings 29 act against plate 31 to urge it quickly upwardly serving toeject punch element 16 outwardly of hole 37 and partially axiallyoutwardly of opening 24 guided in a straight line by the coaxialalignment of plates 26, 31, each engaging the side wall of opening 24.This action makes it easier on the workman by minimizing the lifting andhandling of the tool into and out of the various holes.

According to another embodiment wherein prime marked numbers areemployed for those components comparable to those previously described,a conical self-centering helical spring 41 threadedly engages threadsformed beneath a continuation of the lower end of impact collar 42formed on the lower end of staff 36. A guide plate 43 fits snugly withinopening 24 and is formed with a coaxial opening 44 therethrough forpassing punch element 46 into and out of engagement with the top surfaceof utility channel 11' of a type wherein a number of electric (or othertype) cables may be disposed.

As thus arranged, the lower end of staff 36 includes a tubular downwardextension 48 formed with interior threads for engaging a threadedretainer plug 49 having an enlarged head thereon.

Guide plate 43 includes a counterbored portion 50 having a centralopening 51 slidably disposed loosely about extension 48. The enlargedhead of plug 49 engages the margin of portion 50 around opening 51 so asto couple plate 43 to the lower end of staff 36 while permitting theplate to move between advanced and retracted positions along punchelement 46.

The shoulder 47 of impact collar 42 protects the upper convolution ortwo of spring 41 from being dislodged or otherwise damaged when the toolis generally being handled otherwise than for the purposes as describedherein.

The conical spring 41 has a self-centering action which assists theworker in guiding the punch element 46 directly against the top ofutility channel 1 1 As before, when hammer element 19' strikes the uppersurface of impact collar 42, punch element 46 is driven sharplydownwardly and spring 41 immediately compressed. lnstantly, thereafter,the compressed spring 41 serves to eject punch element 46 upwardly inopening 24' in substantially a straight line due to the conical natureof spring 41. Thus, by using the conical spring 41, a reverse thrust isapplied to the tool directly upwardly and coaxially of opening 24'during the ejecting movement of punch 46.

Finally, in certain applications under the right circumstances, it maybe desirable to eliminate hammer 19 and part of staff 13 above thestriking surface of impact collar 42. Thus, as shown in FIG. 5, a numberof the self-centering punch elements (without substantial staffs andhammer parts) can be disposed in advance in a number of openings 24" andthen a worker can follow with a sledge hammer or other large hammer tostrike each of these guided punch assemblies 55 in order to provide therequisite pilot hole in utility channels or the like.

From the foregoing, it will be readily evident that there has beenprovided an improved tool for simplifying the otherwise somewhatproblemmatical locating of the center for a circle saw cut to be madethrough the top of a utility channel surface or the like.

I claim:

1. A tool for forming pilot holes disposed accurately in a utilitypassage cover or the like for use by a circle saw where the utilitypassage cover is accessible via an opening formed through a layer offlooring material overlying said utility passage, said tool comprisingan elongate staff terminating in a punch portion at one end thereof, ananvil element carried by said staff at one end, a hammer element mountedexteriorly of the staff and movable along said staff into and out ofengagement with said anvil element for striking blows thereagainst todrive said punch portion, and guide means carried about said punchportion for engaging the side walls of said opening and formed to permitsaid punch portion to move freely therethrough during driving of saidpunch portion.

2. A tool according to claim 1 including resilient means disposedbetween said guide means and said one end of the staff for yieldablysupporting said guide means from said one end of the staff and servingto resiliently eject said staff and punch portion axially outwardly insaid opening after each said blow.

3. A tool according to claim 1 in which said guide means includes aplate and means disposing said plate transversely of the axis of saidstaff at said one end, the lateral expanse of said plate correspondingsubstantially to that of said opening, said plate being open coaxiallyof said punch portion to permit the latter to pass therethrough inresponse to each blow.

4. A tool according to claim 3 including a second plate extendinglaterally of said staff and spaced axially of the first plate, elongateguide rods extending between the first named plate and said secondplate, said rods being movable through each of the plates, and resilientmeans disposed between the plates for urging the plates apart, andretaining elements serving to limit said urging so as to maintain theplates disposed about said punch portion.

5. A tool according to claim 1 wherein said punch portion comprises anelement discrete from said staff, and further comprising readilyattachable means carried by said staff and punch portion in readilycoupled relation to attach said portion to the end of said staff.

6. A tool for forming pilot holes disposed accurately in a utilitypassage cover or the-like for use by a circle saw where the utilitypassage cover is accessible via an opening formed through a layer offlooring material overlying said utility passage, said tool comprisingan elongate staff terminating in a punch portion at one end thereof, ananvil element carried by said staff at said one end, a hammer elementmounted externally of the staff and movable along said staff into andout of engagement with said anvil element for striking blowsthereagainst to drive said punch, and a guide plate carried about saidpunch portion and means disposing said guide plate transversely of theaxis of said staff at said one end, the lateral expanse of said platecorresponding substantially to that of said opening for engaging andguiding upon the side walls of said opening and including an openportion permitting said punch portion to move freely therethrough duringdriving of said punch in response to each blow, and resilient meansdisposed between said guide plate and said one end of the staff saidpunch element and movable relative to each other in response toapplication of each blow to said punch element, said plates serving toengage the side walls of said opening for aligning said punch elementwithin said opening, and spring means interposed between said plates forresiliently maintaining said plates apart.

9. A tool for locating a pilot hole for a circle saw in a utilitypassage cover at the bottom of an opening in a layer of flooringmaterial overlying the utility passage, said tool comprising an axiallyextending elongated staff, a punch affixed to the staff at one endthereof, an anvil element affixed to the staff toward said end andextending radially outwardly from said staff, a hammer member mounted onthe staff and movable axially thereof for striking the anvil elementwhen moved toward the one end of the staff, cooperative means carried bythe staff and hammer member for limiting the movement of the hammermember in the direction opposite to the one end, a guide plate having agenerally planar axially facing surface for engaging the upper surfaceof the utility passage cover when placed in the opening in the flooringmaterial and a centrally disposed opening through which the punch canpass, means mounting the guide plate at the one end of the staff withthe opening in the plate aligned with the punch, resilient meansyieldably urging the plate axially away from the staff, and meanslimiting the movement of the plate away from the staff.

10. A tool as in claim 9 wherein the resilient means comprises aconically shaped compression spring having a small end affixed to theend of the staff and a large end engaging the guide plate.

1. A tool for forming pilot holes disposed accurately in a utilitypassage cover or the like for use by a circle saw where the utilitypassage cover is accessible via an opening formed through a layer offlooring material overlying said utility passage, said tool comprisingan elongate staff terminating in a punch portion at one end thereof, ananvil element carried by said staff at one end, a hammer element mountedexteriorly of the staff and movable along said staff into and out ofengagement with said anvil element for striking blows thereagainst todrive said punch portion, and guide means carried about said punchportion for engaging the side walls of said opening and formed to permitsaid punch portion to move freely therethrough during driving of saidpunch portion.
 2. A tool according to claim 1 including resilient meansdisposed between said guide means and said one end of the staff foryieldably supporting said guide means from said one end of the staff andserving to resiliently eject said staff and punch portion axiallyoutwardly in said opening after each said blow.
 3. A tool according toclaim 1 in which said guide means includes a plate and means disposingsaid plate transversely of the axis of said staff at said one end, thelateral expanse of said plate corresponding substantially to that ofsaid opening, said plate being open coaxially of said punch portion topermit the latter to pass therethrough in response to each blow.
 4. Atool according to claim 3 including a second plate extending laterallyof said staff and spaced axially of the first plate, elongate guide rodsextending between the first named plate and said second plate, said rodsbeing movable through each of the plates, and resilient means disposedbetween the plates for urging the plates apart, and retaining elementsserving to limit said urging so as to maintain the plates disposed aboutsaid punch portion.
 5. A tool according to claim 1 wherein said punchportion comprises an element discrete from said staff, and furthercomprising readily attachable means carried by said staff and punchportion in readily coupled relation to attach said portion to the end ofsaid staff.
 6. A tool for forming pilot holes disposed accurately in autility passage cover or the like for use by a circle saw where theutility passage cover is accessible via an opening formed through alayer of flooring material overlying said utility passage, said toolcomprising an elongate staff terminating in a punch portion at one endthereof, an anvil element carried by said staff at said one end, ahammer element mounted externally of the staff and movable along saidstaff into and out of engagement with said anvil element for strikingblows thereagainst to drive said punch, and a guide plate carried aboutsaid punch portion and means disposing said guide plate transversely ofthe axis of said staff at said one end, the lateral expanse of saidplate corresponding substantially to that of said opening for engagingand guiding upon the side walls of said opening and including an openportion permitting said punch portion to move freely therethrough duringdriving of said punch in response to each blow, and resilient meansdisposed between said guide plate and said one end of the staff forsupporting said guide plate from said one end of the staff and servingto resiliently eject said staff and punch portion axially outwardly Insaid opening after each said blow.
 7. A tool according to claim 6wherein said resilient means comprises a conically shaped springinterposed between said one end of said staff and said guide plate.
 8. Atool according to claim 1 wherein said guide means comprises a pair ofspaced plates carried about said punch element and movable relative toeach other in response to application of each blow to said punchelement, said plates serving to engage the side walls of said openingfor aligning said punch element within said opening, and spring meansinterposed between said plates for resiliently maintaining said platesapart.
 9. A tool for locating a pilot hole for a circle saw in a utilitypassage cover at the bottom of an opening in a layer of flooringmaterial overlying the utility passage, said tool comprising an axiallyextending elongated staff, a punch affixed to the staff at one endthereof, an anvil element affixed to the staff toward said end andextending radially outwardly from said staff, a hammer member mounted onthe staff and movable axially thereof for striking the anvil elementwhen moved toward the one end of the staff, cooperative means carried bythe staff and hammer member for limiting the movement of the hammermember in the direction opposite to the one end, a guide plate having agenerally planar axially facing surface for engaging the upper surfaceof the utility passage cover when placed in the opening in the flooringmaterial and a centrally disposed opening through which the punch canpass, means mounting the guide plate at the one end of the staff withthe opening in the plate aligned with the punch, resilient meansyieldably urging the plate axially away from the staff, and meanslimiting the movement of the plate away from the staff.
 10. A tool as inclaim 9 wherein the resilient means comprises a conically shapedcompression spring having a small end affixed to the end of the staffand a large end engaging the guide plate.